Hip joint prosthesis stem system

Abstract

The application discloses a hip joint prosthesis femoral stem system, and belongs to the technical field of orthopedic implants. The hip joint prosthesis femoral stem system comprises a plurality of femoral stems with gradually increased stem lengths. The femoral stem has a proximal first position P1. At the P1 position, the distance from a point with the outside as a starting point and a length accounting for X1 of the total length in the anteroposterior direction of the center line of the cross section of the stem body to the front / rear edge of the stem body is D1. The femoral stem has a distal second position P2. At the P2 position, the thickness between the front and rear edges of the stem body at a point with the outside as a starting point and a length accounting for X2 of the total length in the anteroposterior direction of the center line of the cross section of the stem body is D2. The ratio of D1 to D2 ranges from 0.47 to 0.91. The hip joint prosthesis femoral stem system is suitable for the size ratio of the human medullary cavity, and the anteroposterior direction will not shake. The distal end in the anteroposterior direction will not be pressed and fitted before the proximal end, and tends to be stably fixed in the medullary cavity.

Description

Technical Field

[0001] This invention relates to the field of orthopedic implant technology, and in particular to a hip joint prosthesis femoral stem system. Background Technology

[0002] For hip joint cement stems, the thickness of the stem has little impact on stability because the cement provides additional rotational stability. When using biological femoral stems (non-cemented stems), the press fit between the femoral stem and the natural bone is crucial.

[0003] In hip surgery, medullary reamers are typically used, starting with the smallest size and gradually increasing in size. Percussion is stopped when the reamer cannot be advanced further after tapping and has achieved axial stability. At this point, the required prosthesis size (the prosthesis and medullary reamer should be the same size) can be determined. However, traditional prostheses often experience distal impingement within the medullary canal, resulting in a large proximal gap. This large gap significantly affects the compression fit of the proximal stem to the proximal cortical bone, leading to a very low strain energy density in the proximal cortical bone. This results in insufficient stimulation and increased susceptibility to bone resorption, leading to proximal osteolysis and a higher risk of prosthesis loosening (see [link to relevant documentation]). Figure 1 ).

[0004] During their research, the inventors discovered that current stem designs mostly prioritize the matching and compression fit of the femoral stem in the medial-lateral direction, often neglecting the filling in the anteroposterior direction. This results in most current stem designs being relatively thin, with a large gap easily appearing at the proximal end. While this provides some compression fit in the medial-lateral direction during clinical use, it leads to wobbling in the anteroposterior direction. Furthermore, compression fitting the distal end before the proximal end in the anteroposterior direction is also undesirable, as it makes the femoral stem tend to be unstable in the medullary canal. Therefore, defining the proximal-distal ratio in the anteroposterior direction is crucial. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a hip joint prosthesis femoral stem system that is suitable for the size ratio of the human medullary cavity, does not wobble in the anterior-posterior direction, does not press the distal end before the proximal end in the anterior-posterior direction, and tends to be stably fixed in the medullary cavity.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A hip joint prosthesis femoral stem system includes multiple femoral stems with gradually increasing stem lengths, wherein:

[0008] The femoral stem has a proximal first position P1. At position P1, a point is taken on the center line of the cross-section of the femoral stem body in the anterior-posterior direction, with the outer side as the starting point and the length being X1, which accounts for a proportion of the total length in the anterior-posterior direction, and the distance from the point to the anterior / posterior edge of the stem body is D1, where X1∈(0%,100%).

[0009] The femoral stem has a distal second position P2. At position P2, the thickness between the anterior and posterior edges of the stem body is D2, which is a point on the center line of the cross-section of the femoral stem body in the anterior-posterior direction, starting from the outer side and having a length that is X2 in proportion to the total length in the anterior-posterior direction. Where X2 ∈ (0%, 100%).

[0010] The ratio of D1 to D2 ranges from 0.47 to 0.91.

[0011] Furthermore, the femoral stem is thicker on the outer side and thinner on the inner side at position P1, with the point of maximum thickness being the point corresponding to X1 taking the value of [5%, 40%] at position P1;

[0012] And / or, when X1 takes the value of (0%, 85%) and X2 takes the value of (15%, 85%), the ratio of D1 to D2 ranges from 0.47 to 0.91.

[0013] Furthermore, the initial position is taken as the junction of the uppermost edge of the inner side of the femoral stem with the bone. The first position P1 is within 0-40 mm from the initial position toward the distal end of the femoral stem; the second position P2 is within 50-80 mm from the initial position toward the distal end of the femoral stem.

[0014] Furthermore, the length of each of the multiple femoral stems is within the range of 95mm-143mm, the first position P1 is the initial position, and the second position P2 is 60mm from the initial position toward the distal end of the femoral stem.

[0015] Furthermore, when X1 takes the value of (0%, 85%) and X2 takes the value of (0%, 100%), the ratio of D1 to D2 gradually decreases as the length of the femoral stem increases.

[0016] Furthermore, at position P1, the width between the inner and outer sides of the femoral stem is taken as D3, where:

[0017] When X1 takes values ​​of (0%, 100%), the rate of change of the ratio of D1 to D3 is less than or equal to 10% as the length of the femoral stem increases;

[0018] And / or, at position P1, the width between the inner and outer sides of the femoral stem body is taken as D3, where:

[0019] When X1 takes values ​​of (5%, 75%), the ratio of D1 to D3 ranges from 0.2 to 0.5.

[0020] Furthermore, the femoral stem satisfies the following functional relationship:

[0021] Y = kx + b;

[0022] Where Y is the ratio of D1 to D2 when X1 is 75% and X2 is 50%;

[0023] X is the ratio of D1 to D2 when X1 is 5% and X2 is 50%.

[0024] k is a proportionality coefficient, and the value of k ranges from 0.3 to 0.5;

[0025] b is an adjustment parameter, and the value of b ranges from 0 to 0.5.

[0026] Furthermore, the value of k ranges from 0.36 to 0.49; the value of b ranges from 0.03 to 0.5.

[0027] Furthermore, when the length of the femoral stem is in the range of [95mm, 98mm], X1 is (0%, 85%) and X2 is 50%, the ratio of D1 to D2 is in the range of 0.59-0.91.

[0028] Furthermore, when X1 is 5%, the ratio of D1 to D2 ranges from 0.62 to 0.90.

[0029] And / or, when X1 is 10%, the ratio of D1 to D2 ranges from 0.75 to 0.91;

[0030] And / or, when X1 is 20%, the ratio of D1 to D2 ranges from 0.81 to 0.90;

[0031] And / or, when X1 is 25%, the ratio of D1 to D2 ranges from 0.80 to 0.87;

[0032] And / or, when X1 is 50%, the ratio of D1 to D2 ranges from 0.61 to 0.74;

[0033] And / or, when X1 is 75%, the ratio of D1 to D2 ranges from 0.59 to 0.66.

[0034] The present invention has the following beneficial effects:

[0035] The hip joint prosthesis femoral stem system of the present invention provides a more suitable choice of medullary canal setting for real-life individuals. By limiting the range of the ratio between the distance D1 from the point on the center line of the proximal femoral stem in the anteroposterior direction of the cross-section, with a length equal to X1 (based on the outer side) to the anterior / posterior edge of the stem, and the thickness D2 between the anterior / posterior edges of the stem at the point on the center line of the distal femoral stem in the anteroposterior direction of the cross-section, with a length equal to X2 (based on the outer side) and the distal femoral stem, the femoral stem is made more suitable for the medullary canal size ratio of the human body, thereby improving the fit between the proximal and distal femoral stems in non-human-centered environments. In cemented femoral stem fixation, the proximal end of the femoral stem can be filled in the anterior-posterior space, making the femoral stem more stable in the anterior-posterior direction and preventing wobbling. It also allows for better matching design between the proximal and distal ends, so that while considering the size of the distal medullary canal, the proximal end can be well pressed and fitted. Furthermore, the distal end will not press and fit before the proximal end in the anterior-posterior direction, making the femoral stem tend to be stable and fixed in the medullary canal. This increases the strain energy density of the proximal end, stimulates bone growth, and reduces the risk of prosthesis loosening. It is particularly beneficial for the long-term fixation of uncemented femoral stems, resulting in good postoperative outcomes. Attached Figure Description

[0036] Figure 1 A schematic diagram illustrating the mechanical properties of a hip joint prosthesis femoral stem after implantation into the human body in the prior art.

[0037] Figure 2 A schematic diagram showing the selection of the measurement position for the femoral stem of a hip joint prosthesis in the prior art;

[0038] Figure 3 This diagram illustrates the selection of the measurement location for the femoral stem of the hip joint prosthesis in this invention. Figure 1 ;

[0039] Figure 4 This diagram illustrates the selection of the measurement location for the femoral stem of the hip joint prosthesis in this invention. Figure 2 ;

[0040] Figure 5 This is a schematic cross-section of the femoral stem of the hip joint prosthesis at position P1 in this invention. Figure 1 ;

[0041] Figure 6 This is a schematic cross-section of the femoral stem of the hip joint prosthesis at position P1 in this invention. Figure 2 ;

[0042] Figure 7 This is a schematic diagram of the mechanical properties of the hip joint prosthesis femoral stem after implantation in the human body according to the present invention. Detailed Implementation

[0043] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0044] Noble first described the shape of the femoral medullary canal in his research, which was represented by a single geometric parameter called the spinal canal expansion index, defined as the ratio of the width of the femoral cortex at 20 mm proximal to the isthmus. However, later studies found that initial fixation of the femoral stem often failed to reach the isthmus. Therefore, the ratio P / D of the distal (60 mm below the lesser trochanter) and proximal (10 mm above the lesser trochanter) cross-sections in the coronal plane is commonly used to study the femoral stem matching (see [link to study]). Figure 2 ).

[0045] However, the above indices are indices in the ML (medial) direction, while indices in the AP (anteroposterior) thickness direction have been rarely studied. Because the shape of the medullary canal varies from person to person, femoral stem matching requires not only to occur in the coronal plane but also in a three-dimensional space in the anteroposterior direction.

[0046] In view of this, the present invention provides a hip joint prosthesis femoral stem system, such as Figure 3-7 As shown, it includes multiple femoral stems with gradually increasing stem lengths (the femoral stem includes a stem body 1 and a femoral neck 2), wherein:

[0047] The femoral stem has a proximal first position P1. At position P1, take the distance D1 from the anterior / posterior edge of the stem body 1 to the center line M of the cross-section of the femoral stem body 1 in the anterior-posterior direction, starting from the outer side and having a length of X1 that accounts for a proportion of the total length in the anterior-posterior direction. Where X1∈(0%,100%).

[0048] The femoral stem has a distal second position P2. At position P2, the thickness between the anterior and posterior edges of the stem body 1 is D2, which is a point on the center line M of the cross-section of the femoral stem body 1 in the anterior-posterior direction, with the outer side as the starting point and the length being X2, which accounts for the proportion of the total length in the anterior-posterior direction. Where X2∈(0%,100%).

[0049] The ratio of D1 to D2 ranges from 0.47 to 0.91.

[0050] The hip joint prosthesis femoral stem system of the present invention provides a more suitable choice of medullary canal setting for real-life individuals. By limiting the range of the ratio between the distance D1 from the point on the center line of the proximal femoral stem in the anteroposterior direction of the cross-section, with a length equal to X1 (based on the outer side) to the anterior / posterior edge of the stem, and the thickness D2 between the anterior / posterior edges of the stem at the point on the center line of the distal femoral stem in the anteroposterior direction of the cross-section, with a length equal to X2 (based on the outer side) and the distal femoral stem, the femoral stem is made more suitable for the medullary canal size ratio of the human body, thereby improving the fit between the proximal and distal femoral stems in non-human-centered environments. In cemented femoral stem fixation, the proximal end of the femoral stem can be filled in the anterior-posterior space, making the femoral stem more stable in the anterior-posterior direction and preventing wobbling. It also allows for better matching design between the proximal and distal ends, so that while considering the size of the distal medullary canal, the proximal end can be well pressed and fitted. Furthermore, the distal end will not press and fit before the proximal end in the anterior-posterior direction, making the femoral stem tend to be stable and fixed in the medullary canal. This increases the strain energy density of the proximal end, stimulates bone growth, and reduces the risk of prosthesis loosening. It is particularly beneficial for the long-term fixation of uncemented femoral stems, resulting in good postoperative outcomes.

[0051] Furthermore, the femoral stem body 1 is thicker on the lateral side and thinner on the medial side at position P1 (see...). Figure 5-6 The point with the maximum thickness is the point at position P1 where X1 takes the value [5%, 40%]. Specifically, Figure 5 In this example, D1 is represented as AP1, AP2, ..., AP10. The maximum value of D1 is between 5% and 40%, for example, it can be 5%, 7%, 10%, 15%, 17%, 20%, 23%, 25%, 30%, 35%, etc. In this embodiment, the maximum value of D1 is between 20% and 40%. Preferably, when X1 is (0%, 85%) and X2 is (15%, 85%), the ratio of D1 to D2 is between 0.47 and 0.91.

[0052] Preferred, such as Figure 3-4 As shown, the initial position is taken at the junction of the uppermost edge of the medial side of the femoral stem body 1 and the bone. Figure 3-4 The first position P1 is within 0-40mm from the initial position towards the distal end of the femoral stem; the second position P2 is within 50-80mm from the initial position towards the distal end of the femoral stem, at which point the femoral stem matching effect is optimal. In specific implementation, the first position P1 can be the initial position, and the second position P2 is 60mm from the initial position towards the distal end of the femoral stem.

[0053] In this invention, the femoral stem can be divided into different models according to different stem lengths, and the stem lengths of multiple femoral stems (specifically referring to the inner stem length, i.e., the distance from the initial position to the lowest end of the stem body 1) can all be within the range of 95mm-143mm.

[0054] For a single femoral stem, to define the shape / size of the femoral stem, when the stem length is in the range of [95mm, 98mm], X1 is (0%, 85%), and X2 is 50%, the ratio of D1 to D2 can range from 0.59 to 0.91. Furthermore, when X1 is 5% (i.e., AP1 in the figure), the ratio of D1 to D2 can range from 0.62 to 0.90.

[0055] To better define the shape / size of the femoral stem, this invention preferably takes a position P1 on the center line M of the cross-section of the femoral stem body 1 in the anterior-posterior direction, starting from the outer side, within a range of (0%, 85%) of the total length in the anterior-posterior direction, excluding the 5% distance (i.e., AP1 in the figure). Other positions are then selected at these additional positions beyond the 5% distance to further define the dimensional variation of the femoral stem, thus better suiting the ratio of the medullary canal size to the human body. In specific implementations, for example:

[0056] When the length of the femoral stem is in the range of [95mm, 98mm], X1 is 10% (i.e. AP2 in the figure) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.75-0.91.

[0057] When the length of the femoral stem is in the range of [95mm, 98mm], X1 is 20% (i.e., AP4 in the figure) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.81-0.90.

[0058] When the length of the femoral stem is in the range of [95mm, 98mm], X1 is 25% (i.e. AP5 in the figure) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.80-0.87.

[0059] When the length of the femoral stem is in the range of [95mm, 98mm], X1 is 50% (i.e. AP11 in the figure) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.61-0.74.

[0060] When the length of the femoral stem is in the range of [95mm, 98mm], X1 is 75% (i.e. AP6 in the figure) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.59-0.66.

[0061] For example, when the length of the femoral stem is in the range of [98mm, 105mm], X1 is (0%, 85%) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.55-0.87.

[0062] For example, when the length of the femoral stem is in the range of [105mm, 108mm], X1 is (0%, 85%) and X2 is 50%, the ratio of D1 to D2 can be in the range of 0.53-0.89.

[0063] For multiple femoral stems, to limit the shape / size of the femoral stems, when X1 can be (0%, 85%) and X2 can be (0%, 100%), the ratio of D1 to D2 gradually decreases as the length of the femoral stem increases (see the variation pattern of any column in Table 1 below).

[0064] like Figure 6 As shown, the width between the inner and outer sides of the femoral stem at position P1 is defined as D3 (i.e., ML in the figure), where:

[0065] For multiple femoral stems, when X1 is taken as (0%, 100%), as the length of the femoral stem increases, the rate of change of the ratio of D1 to D3 is preferably less than or equal to 10%, that is, the ratio of D1 to D3 is relatively constant among prostheses of different sizes, and there is no obvious trend of change with the size / model of the femoral stem.

[0066] For a single femoral stem, when X1 is (5%, 75%), the ratio of D1 to D3 can be in the range of 0.2-0.5, which better defines the shape / size of the femoral stem.

[0067] It is understandable that the P1 position can be any other position within 0-40mm from the initial position toward the distal end of the femoral stem, such as 11mm, 12mm, 13mm, 20mm, 35mm, 40mm, etc.; the X1 value can be any other position within the range of (0%, 85%), such as 15% (i.e., AP3 in the figure), 80% (i.e., AP7 in the figure), 85% (i.e., AP8 in the figure), etc.; the P2 position can also be any other position within 50-80mm from the initial position toward the distal end of the femoral stem, such as 50mm, 51mm, 62mm, 70mm, 73mm, 80mm, etc.; the X2 value can be any other position within the range of (0%, 100%), such as 15%, 20%, 30%, 70%, 80%, 85%, 90%, etc.

[0068] This invention primarily targets cementless hip prostheses. Total hip arthroplasty typically comprises three parts: the femoral stem, the liner, and the outer cup. The femoral stem is divided into a stem body portion 1 and a femoral neck portion 2. This invention can increase the thickness of the proximal femoral stem within 0-40mm and at any position above 0mm. This cementless femoral stem can be available in N sizes. The thickness (D1) at different percentages of the proximal cross-section from 0% to 85% in the anteroposterior three-dimensional space is defined as the ratio of the thickness D2 between the anterior and posterior edges of the 60mm cross-section. By studying the patterns of the proximal stem thickness AP to ML ratio for prostheses of various sizes, suggestions are made for optimized thickening parameters for each size. The optimal match of the femoral stem is determined by the D1 to D2 ratio, maximizing the proximal anteroposterior compression fit for each individual, thereby achieving good anterior and posterior filling and stability in cementless femoral stem fixation.

[0069] The femoral stem of the hip joint prosthesis in this invention will be described below with a specific example. This invention is particularly applicable to uncemented hip joint prostheses with femoral stems. The following description uses an uncemented hip joint prosthesis with femoral stem as an example, defining the range of the ratio of D1 to D2 when X1 is (0%, 85%) and X2 is 50% at the first position P1 (0mm in the table) and the second position P2 (60mm in the table), thereby achieving a better match. In this embodiment, the hip joint prosthesis femoral stem system includes ten femoral stem prostheses depending on the stem length range. In other embodiments, the number of femoral stem prostheses can be adjusted according to different actual usage requirements.

[0070] The preferred range of the D1 to D2 ratio for the femoral stem of the uncemented hip prosthesis in this embodiment is shown in Table 1 below.

[0071] Table 1 (Handle length in mm)

[0072]

[0073] Table 1 above provides a femoral stem design with a more suitable ratio to the human medullary canal size, and offers recommendations for the femoral stem size for each model. Values ​​can be the same or different within a given range. Furthermore, the table shows that the ratio of D1 to D2 gradually decreases as the femoral stem model / size increases.

[0074] In Table 1, to better define the shape / size of a single femoral stem, the femoral stem preferably satisfies the following functional relationship:

[0075] Y = kx + b;

[0076] Where Y is the ratio of D1 to D2 when X1 is 75% and X2 is 50%;

[0077] X is the ratio of D1 to D2 when X1 is 5% and X2 is 50%.

[0078] k is a proportionality coefficient, and the value of k ranges from 0.3 to 0.5;

[0079] b is an adjustment parameter, and the value of b ranges from 0 to 0.5.

[0080] Furthermore, the value of k can be in the range of 0.36-0.49, such as 0.37, 0.38, 0.40, 0.45, 0.48, etc.; the value of b can be in the range of 0.03-0.5, such as 0.03, 0.1, 0.15, 0.2, 0.3, 0.45, 0.5, etc.

[0081] After testing, such as Figure 1 As shown, existing uncemented hip prostheses, i.e., those without improvements, have a large proximal femoral stem gap, low strain energy density, and are prone to bone resorption, resulting in a 99.7% mismatch rate; for example... Figure 7 As shown, the present invention is used Figure 3-6 When the uncemented hip prosthesis femoral stem shown in Table 1 has the dimensional data, 99.7% of the above-mentioned individuals achieved a good proximal fit without any change in distal dimensions. The high strain energy density is conducive to bone growth, resulting in a good fit for the vast majority of people. In addition, the medial interference rate was reduced from nearly 10% to less than 1%, resulting in an overall good fit rate of over 98%.

[0082] Therefore, this invention designs the shape of the femoral stem prosthesis according to the laws of the human medullary cavity, providing a more suitable choice of medullary cavity setting for real people. This increases the proximal thickness of the femoral stem in cementless stem fixation, increases the filling of the anterior-posterior space of the proximal femoral stem, makes the femoral stem more stable in the anterior-posterior direction, prevents wobbling in the anterior-posterior direction, effectively performs proximal compression fitting, improves the strain energy density of the proximal end, stimulates bone growth, and reduces the likelihood of prosthesis loosening. It is particularly beneficial for the long-term fixation of cementless femoral stems, achieving good postoperative results. At the same time, it provides suggestions for optimizing the thickening parameters of femoral prostheses of each size, thereby achieving good anterior-posterior filling and anterior-posterior stability in cementless stem fixation.

[0083] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A hip joint prosthesis femoral stem system, characterized in that, It includes multiple femoral stems with gradually increasing stem lengths, among which: The femoral stem has a proximal first position P1. At position P1, a point is taken on the center line of the cross-section of the femoral stem body in the anterior-posterior direction, with the outer side as the starting point and the length being X1, which accounts for a proportion of the total length in the anterior-posterior direction, and the distance from the point to the anterior / posterior edge of the stem body is D1, where X1∈(0%,100%). The femoral stem has a distal second position P2. At position P2, the thickness between the anterior and posterior edges of the stem body is D2, which is a point on the center line of the cross-section of the femoral stem body in the anterior-posterior direction, starting from the outer side and having a length that is X2 in proportion to the total length in the anterior-posterior direction. Where X2 ∈ (0%, 100%). The femoral stem is thicker on the outer side and thinner on the inner side at position P1. The point with the maximum thickness is the point corresponding to the value of X1 at position P1 when it is [5%, 40%]. When X1 takes the value of (0%, 85%) and X2 takes the value of (15%, 85%), the ratio of D1 to D2 ranges from 0.47 to 0.

91. The initial position is taken as the junction between the uppermost edge of the inner side of the femoral stem and the bone. The stem length of the multiple femoral stems is in the range of 95mm-143mm. The stem length is the distance from the initial position to the lowermost end of the femoral stem body. The first position P1 is the initial position, and the second position P2 is 60mm from the initial position toward the distal end of the femoral stem. The femoral stem is a cementless femoral stem.

2. The hip joint prosthesis femoral stem system according to claim 1, characterized in that, When X1 takes the value of (0%, 85%) and X2 takes the value of (0%, 100%), the ratio of D1 to D2 gradually decreases as the length of the femoral stem increases.

3. The hip joint prosthesis femoral stem system according to claim 1, characterized in that, At position P1, the width between the inner and outer sides of the femoral stem body is taken as D3, where: When X1 takes values ​​of (0%, 100%), the rate of change of the ratio of D1 to D3 is less than or equal to 10% as the length of the femoral stem increases; And / or, at position P1, the width between the inner and outer sides of the femoral stem body is taken as D3, where: When X1 takes values ​​of (5%, 75%), the ratio of D1 to D3 ranges from 0.2 to 0.

5.

4. The hip joint prosthesis femoral stem system according to claim 1, characterized in that, The femoral stem satisfies the following functional relationship: Y = kx + b; Where Y is the ratio of D1 to D2 when X1 is 75% and X2 is 50%; X is the ratio of D1 to D2 when X1 is 5% and X2 is 50%. k is a proportionality coefficient, and the value of k ranges from 0.3 to 0.5; b is an adjustment parameter, and the value of b ranges from 0 to 0.

5.

5. The hip joint prosthesis femoral stem system according to claim 4, characterized in that, The value of k ranges from 0.36 to 0.49; the value of b ranges from 0.03 to 0.

5.

6. The hip joint prosthesis femoral stem system according to claim 1, characterized in that, When the length of the femoral stem is in the range of [95mm, 98mm], and X1 is (0%, 85%) and X2 is 50%, the ratio of D1 to D2 is in the range of 0.59-0.

91.

7. The hip joint prosthesis femoral stem system according to claim 6, characterized in that, When X1 is 5%, the ratio of D1 to D2 ranges from 0.62 to 0.

90. And / or, when X1 is 10%, the ratio of D1 to D2 ranges from 0.75 to 0.91; And / or, when X1 is 20%, the ratio of D1 to D2 ranges from 0.81 to 0.90; And / or, when X1 is 25%, the ratio of D1 to D2 ranges from 0.80 to 0.87; And / or, when X1 is 50%, the ratio of D1 to D2 ranges from 0.61 to 0.74; And / or, when X1 is 75%, the ratio of D1 to D2 ranges from 0.59 to 0.66.

Images